There are lots of examples of routine, middle-skilled jobs that involve relatively structured tasks, and those are the jobs that are being eliminated the fastest. Those kinds of jobs are easier for our friends in the artificial intelligence community to design robots to handle them. They could be software robots; they could be physical robots.

Going a little further into the future, we'll start literally connecting to machines. Some of my colleagues at MIT here - some of them are working on a neural mesh that connects directly to your brain, and they've already done it with some disabled people and allowed them to move objects just by thinking.

Technology is always creating jobs. It's always destroying jobs.

Machines already are much smarter than us at so many things. I mean, try to multiply two 10-digit numbers with each other or, you know, sift through a thousand documents. So there's lots of things that machines are better at including in mental task than us. There's many more that they're not as good at, but the direction is pretty obvious and the progress is clear.

Now comes the second machine age. Computers and other digital advances are doing for mental power - the ability to use our brains to understand and shape our environments-what the steam engine and its descendants did for muscle power.

The economy in the next 20 to 25 years is going to change more than they did in the last 20, 25 years. And that's because exponential trends are affecting a bigger and bigger share of the economy. So we have some huge disruptions in store, and I can't predict exactly what the innovations are going to be. If I did, I would have already invented them. But I think they'll be comparable to the innovations we saw in the past 20, 25 years if not greater.

It's most useful to think about not jobs but tasks. And within any given job, there are lots of different tasks. If you're a radiologist maybe reading the images machines can be able to do that better, maybe making the broader diagnosis and communicating it to the patients.